In the latest version of WhatsApp videos from YouTube, Instagram and Facebook look a little in a different way in a preview window. Now, having pressed the button of reproduction of video, you can move a window with video to any point of the screen. The current session of WhatsApp remains active therefore you can continue to write or read messages in the usual mode.
Now the "picture in the picture" mode, it seems, works only for YouTube, Facebook and Instagram, and video, for example, from Twitter is not started. To watch PiP-video already now it is necessary to update a messenger to the WhatsApp Beta v2.18.301 version. It is possible to wait for updating from Play Store or to download it manually from APK Mirror.
By the way, the domestic ICQ messenger a little in what concedes to WhatsApp. In addition to group calls, it has also other strengths which the child of Facebook does not have. "ICQ" supports pins of messages and a mention of users in them, search and editing the sent messages and also stickers (search in sets, emodz and other)